1. Technical Field
The present invention relates to a spectroscopic image capturing apparatus.
2. Related Art
As is known, it is sometimes desirable to acquire information on the components or content of an object while keeping the object intact. To accomplish this, there is a widely used method for capturing spectral image data on the object and analyzing the data to produce, for example, component information. For example, JP-A-2000-329617 discloses a method for acquiring spectral data on a specific portion of an object. In this method, an image data acquisition apparatus captures an image of the entire object to acquire an image of the object. Also, a spectral data acquisition apparatus acquires spectral data in an area narrower than the acquired image of the object and at a higher wavelength resolution than the image data acquisition apparatus. The image data acquisition apparatus is thus used to acquire general characteristics of the object, while the spectral data acquisition apparatus is used to analyze a characteristic portion of the data in detail and thereby acquire the analysis result. The spectroscopic image input system disclosed in JP-A-2000-329617 accommodates a unit that determines the specific portion and characterizes, that is, analyzes the object in a quick, stable manner without a human operator's judgment.
Further, JP-A-2009-33222 discloses an image capturing apparatus capable of producing a spectroscopic image of an object by using a single-panel digital camera but also using a spectroscopic filter having a narrow-band wavelength transmitting characteristic to acquire captured images of the object while changing the wavelength transmitting band and combining the acquired images of the wavelength bands.
In recent years, however, trends of maintaining health, ensuring food safety, and other requirements increasingly demand a compact food checker and other devices for measuring components, sugar content, and other parameters of a food product. The spectroscopic image input system disclosed in JP-A-2000-329617, however, not only requires the image capturing apparatus for acquiring an image of an entire object but also the spectral data acquisition apparatus for acquiring a spectral image of a specific portion of the object. This results in an increase in the size of the system. Further, providing a compact food checker allows the apparatus to capture an image of a close object, but measurement of food components and other parameters requires measurement of the interior of the object instead of the surface thereof. When a food product whose image is to be captured has a shiny surface, it is necessary to suppress an effect of light specularly reflected off the shiny surface. JP-A-2009-33222 suggests a method used with the image capturing apparatus for capturing an image of an object close thereto but does not disclose compensation for the effect of specular reflection.